Method and apparatus for creasing facing material used in the manufacture of wallboard

ABSTRACT

Aspects of this disclosure relate to a method of manufacturing wallboard which includes providing a first layer of facing material, creasing the first layer facing material intermittently to create a series of creased portions, providing a gypsum slurry on the first layer of facing material and providing a second layer of facing material over the gypsum slurry. Further, creasing the first layer of facing material intermittently can include intermittently creasing the first layer of facing material in a substantially linear fashion extending in a first direction of the first layer of facing material so that the first layer of facing material exhibits a linear series of creased portions extending in the first direction of the first layer of facing material and a series of portions that are not creased extending in the first direction of the first layer of facing material.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional of U.S. patent application Ser. No.13/563,883, filed on Aug. 1, 2012, which is a divisional of U.S. patentapplication Ser. No. 12/267,375, filed on Nov. 7, 2008, each of which ishereby incorporated by reference in its entirety.

FIELD OF THE DISCLOSURE

Aspects of the present disclosure generally relate to manufacturing ofwallboard. Particular aspects of the present disclosure relate to thecreasing of facing material used in wallboard manufacturing process.

BACKGROUND

Wallboard is a manufactured building material that is used in theconstruction of walls or ceilings. Wallboard is also known asplasterboard, drywall and gypsum board. In a conventional process forcreating wallboard, the wallboard is manufactured from a gypsum slurry.The gypsum slurry material is fed on a sheet of facing material at the“wet end” of a wallboard line and then as the gypsum slurry materialtravels down the line, a second sheet of facing material is placed ontop of the slurry material to form the wallboard. The wallboard hardensthrough a chemical reaction. The resulting wallboard is a longcontinuous slab which is cut via a knife into separate lengths. Theresulting lengths are sent through driers which drive excess water outof the gypsum. Crystals of gypsum, and other additives, migrate into thefacing sheet to create a tight bond. Once the wallboard has been dried,it may be “booked” together by a “booker” wherein two lengths ofwallboard are brought together, facing material to facing material, inorder to protect the inner or finished surfaces of the wallboard.Thereafter, the “booked” wallboard may be transferred to a wallboardbundler. The wallboard bundler squares and aligns the wallboard in orderto trim the wallboard to a precise length and tape the ends of the wallboard. After the wallboards have left the bundler they may be sent to astacker which aligns the bundles of wallboard and stacks them on top ofeach other to be transferred to a storage location.

In the above described process, the facing material onto which theslurry is fed may be creased and folded to create the long edges of thewallboard. However, conventional creasing equipment and processes cancut through or at least weaken the facing material. For example,conventional creasing equipment and processes can create weak points inthe edge of the wallboard where the edge of the wallboard can separateand pull away from the core of the wallboard. This will have negativeeffects on both the quality and the aesthetics of the wallboard.Therefore, it would be desirable to crease the facing material in amanner that reduces or eliminates the cutting through or weakening ofthe facing material.

SUMMARY

The present disclosure generally relates to methods and an apparatus forcreasing the facing material used in manufacturing wallboard.

Aspects of this disclosure relate to a method of manufacturing wallboardwhich includes providing a first layer of facing material, creasing thefirst layer facing material intermittently to create a series of creasedportions, providing a gypsum slurry on the first layer of facingmaterial and providing a second layer of facing material over the gypsumslurry. Further, creasing the first layer of facing materialintermittently can include intermittently creasing the first layer offacing material in a substantially linear fashion extending in a firstdirection of the first layer of facing material so that the first layerof facing material exhibits a linear series of creased portionsextending in the first direction of the first layer of facing materialand a series of portions that are not creased extending in the firstdirection of the first layer of facing material.

Additional aspects of this disclosure relate to an apparatus formanufacturing wallboard which includes a feeder that feeds a first layerof facing material, a first set of one or more creaser wheels positionedon a first side of the first layer of facing material, a second set ofone or more creaser wheels positioned on a second side of the firstlayer of facing material and a feeding source that feeds a gypsum slurryon the first layer of facing material. Further, each of the creaserwheels includes a series of notches and teeth. Additionally, eachcreaser wheel creases the first layer of facing material by creasingportions the first layer of facing material and refraining from creasingother portions of first layer facing material so that the uncreasedportions of the first layer of facing material are positioned in linewith the creased portions of the facing material and between the creasedportions of facing material.

Additional aspects of this disclosure relate to a method of preparing afacing material for use in the manufacturing of wallboard which includesproviding a facing material, creasing the facing material by applying afirst set of one or more creaser wheels positioned on a first side ofthe facing material and a second set of one or more creaser wheelspositioned on a second side of the facing material and folding thecreased facing material to create the edge of the wallboard. Further,each of the creaser wheels has notches and teeth and is applied to thefacing material in a rotational manner so that the facing material iscreased in intervals so that the facing material exhibits creasedportions and uncreased portions in line with the creased portionsbetween the creased portions. Additionally, each of the creaser wheelsin the first set of creaser wheels are offset from one another in awidth direction of the facing material, so that the first set of creaserwheels creates a first set of parallel rows of creased portions anduncreased portions extending in a direction along a length of the facingmaterial and each of the creaser wheels in the second set of creaserwheels are offset from one another in a width direction of the facingmaterial, so that the second set of creaser wheels creates a second setof parallel rows of creased portions and uncreased portions extending ina direction along a length of the facing material.

The above summary presents general aspects of the disclosure in order toprovide a basic understanding of at least some of its aspects. Thesummary is not intended as an extensive overview of the disclosure. Itis not intended to identify key or critical elements of the disclosureor to delineate the scope of the disclosure. The above summary merelypresents some concepts of the disclosure in a general form as a preludeto the more detailed description provided below.

BRIEF DESCRIPTION OF THE DRAWINGS

A more complete understanding of the present disclosure and certainadvantages thereof may be acquired by referring to the followingdescription in consideration with the accompanying drawings, in whichlike reference numbers indicate like features, and wherein:

FIG. 1 is a schematic diagram illustrating a process for manufacturingwallboard;

FIG. 2A is a profile view of a wallboard with a rectangular edge;

FIG. 2B is a profile view of a wallboard with a beveled edge;

FIG. 3A illustrates a conventional creaser wheel;

FIG. 3B illustrates a facing material during a process for manufacturingwallboard where the facing material has been creased with conventionalcreaser wheels;

FIG. 4A illustrates a wallboard product wherein the edge has separatedfrom the core of the wallboard;

FIG. 4B illustrates a wallboard product wherein the edge has separatedfrom the core of the wallboard;

FIG. 5A is an illustrative embodiment of a creaser wheel according to anaspect of the present disclosure;

FIG. 5B is another view of the creaser wheel illustrated in FIG. 5A;

FIG. 5C is an enlarged view of a section of the creaser wheelillustrated in FIG. 5A;

FIG. 5D is a end view of the creaser wheel illustrated in FIG. 5A;

FIG. 5E is a sectional view of the creaser wheel illustrated in FIG. 5A;

FIG. 6A is an illustrative embodiment of a creaser wheel according to anaspect of the present disclosure;

FIG. 6B is another view of the creaser wheel illustrated in FIG. 6A;

FIG. 6C is a sectional view of the creaser wheel illustrated in FIG. 6A;

FIG. 6D is a top view of the creaser wheel illustrated in FIG. 6A;

FIG. 6E is an enlarged view of a section of the creaser wheelillustrated in FIG. 6C;

FIG. 7A is an illustrative embodiment of a creaser wheel according to anaspect of the present disclosure;

FIG. 7B is another view of the creaser wheel illustrated in 7A;

FIG. 8 illustrates a set of creaser wheels according to an aspect of thepresent disclosure;

FIG. 9A is an illustrative embodiment of a facing material during aprocess for manufacturing wallboard where the facing material has beencreased according to aspects of this disclosure; and

FIG. 9B is an illustrative embodiment of a facing material during aprocess for manufacturing wallboard where the facing material has beencreased according to aspects of this disclosure.

DETAILED DESCRIPTION

In the following description of various example embodiments of thedisclosure, reference is made to the accompanying drawings, which form apart hereof, and in which are shown by way of illustration variousexample structures and systems in which aspects of the disclosure may bepracticed. It is to be understood that other specific arrangements ofparts, structures, example devices, systems, and the like may beutilized and structural and functional modifications may be made withoutdeparting from the scope of the present disclosure.

FIG. 1 is a schematic diagram which shows an illustrative embodiment ofa portion of a process for creating wallboard wherein a first layer afacing material sheet 1 is being conveyed down a conveying line. Thefacing material may be paper, fiberglass (e.g., a fiberglass mat, acoated fiberglass mat), etc. Each material that can be used as facingmaterial will have its own particular advantages. For example, when amultiply Kraft paper (e.g., a heavy paper) is used as the facingmaterial, it has the advantage of being relatively inexpensive comparedto other materials that could be employed as facing material.Alternatively, when a fiberglass mat is used as facing material,especially a coated fiber glass mat, for example, as described in U.S.Pat. No. 6,808,793, it has advantage of being moisture resistant andmold resistant. Therefore, wallboard constructed with a fiberglass matas the facing material has a greater resistance to moisture and mold,particularly a coated fiberglass mat, as compared with wallboardconstructed with paper as the facing material. Regardless of whatparticular material is used as the facing material, the process ofcreating the wallboard will remain relatively unchanged.

As shown in FIG. 1, the facing material 1 is fed as a long, continuoussheet on which the gypsum slurry is placed. A mixer (not shown) preparesa gypsum slurry material and transmits it to a feed source, such as aslurry boot 3. At the slurry boot 3, the gypsum slurry 5 is distributedonto the facing material sheet 1. In some cases, the slurry boot 3 maycontain one or more outlets which distribute the gypsum slurry moreevenly across the width of the facing material 1. As seen in FIG. 1, asecond layer of facing material sheet 2, in other words, a top or backlayer of facing material, is also conveyed down the conveying line sothat after the gypsum slurry 5 is applied onto the facing material sheet1 at the slurry boot 3, the top facing material sheet 2 is placed on topof the gypsum slurry 5 and the facing material sheet 1 in order to formthe top side face of the wallboard 7. This process of attaching thesecond layer of facing material 2 takes place at a forming station 12which is positioned downstream of a slurry boot 3 as shown in FIG. 1.After the forming station 12, the first layer of facing material 1, thegypsum slurry 5 and the second layer of facing material 2, can be putthrough a dryer station wherein the first layer of facing material 1,the gypsum slurry 5 and the second layer of facing material 2 are dried.

The facing material 1 can be folded in order to create the edges of thewallboard 7. For example, the ends of the facing material 1 can befolded upwards and inwards to create a “pocket” which will hold thegypsum slurry 5 within the facing material sheet 1. For example, FIG. 2Ashows a profile view of a particular embodiment of a wallboard product7. As seen in FIG. 2A, the ends of the facing material sheet 1 arefolded twice to create the “pocket”. Specifically, the facing materialsheet 1 is folded at a first position 9A and at a second position 9B tocreate the edge of the wallboard 7. As seen in FIG. 2A, the folds can beapproximately 90° so that the wallboard 7 has a rectangular edge.Further, as seen in FIG. 2A the facing material sheet 1 is folded sothat a flap 9C is created which forms the top end of the “pocket”. Also,this flap 9C provides a place for the top facing material sheet 2 to beattached to the facing material sheet 1. For example, an adhesive, suchas glue, can be applied to between the two sheets and then the topfacing material sheet 2 can be applied. In this way, the top facingmaterial sheet 2 will form a top side face of the wallboard 7.

FIG. 2B shows an alternative embodiment wherein the facing sheetmaterial 1 is folded four times. Specifically, the facing material sheet1 is folded at a first position 10A, a second position 10B, a thirdposition 10C, and a fourth position 10D in order to create the edge ofthe wallboard 7. As seen the folds are angled so that the wallboard 7has a beveled edge. This wallboard 7 with a beveled edge may be used inparticular applications of the wallboard 7 wherein wallboard with abeveled edge is preferred over wallboard with a rectangular edge. Forexample, the beveled edges allow the wallboard to be hung between twometal channels. Therefore, the beveled edged wallboard could be used toline elevator shafts or in other environments wherein the ability of thewallboard to be hung between two metal channels would be relevant.Again, just as with the above described embodiment, a flap 10E may beemployed, because it provides a place for the top facing material sheet2 to be attached to the facing material sheet 1. As seen in FIG. 2B, anadhesive, such as glue, can be applied to between the two sheets andthen the top facing material sheet 2 can be applied. In this way, thetop facing material sheet 2 will form a top side face of the wallboard7.

It is noted, that these illustrative embodiments are just examples ofthe types of wallboard 7 that can be produced and, of course, othertypes of wallboard 7 are contemplated. For example, other folds such asa triple fold, folds with different angles, etc. could be employedwithout departing from the scope of this disclosure.

The folding of the facing material takes place prior to the facingmaterial entering the forming station 12. For example, after the gypsumslurry is applied to the facing material 1, the width ends of theconveying line are configured to fold the facing material 1 upwards. Forexample, the conveying line may contain upstanding rails that guide andfold the ends of the facing material 1. Further, just prior to enteringthe forming station 12, the conveying line can be configured to fold theends of the facing material over in a manner as described above. Forexample, the conveying line can be configured to fold the facingmaterial 1 approximately 90° at a first position 9A and again 90° at asecond position 9B to create the rectangular edge of the wallboard seenin FIG. 2A. Once the facing material 1 has been folded, the formingstation 12 attaches the top facing material sheet 2 to the facingmaterial 1. For example, the forming station 12 may apply an adhesivesuch as glue between facing material 1 and top facing material sheet 2in order to attach the first and second layers of facing material 1, 2.

In order to facilitate the above described folding of the facingmaterial 1, the facing material 1 may be creased or scored prior thefacing material 1 being folded along the conveying line. In other words,once the facing material 1 has been creased, it can be folded along thecrease. For example, as seen in FIG. 1, a creasing area 11 may bepositioned on the conveying line so that facing material sheet 1 iscreased prior to the gypsum slurry 5 being distributed onto the facingmaterial sheet 1 at a slurry boot 3. Further, as seen in FIG. 1, thecreasing area 11 can include one or more creaser wheels (although it isnoted that other creasing apparatus may be used as well). As the facingmaterial 1 travels down the conveying line and through the creaser area11, the creaser wheels create rows of creases in the facing materialsheet 1.

Conventional creaser wheels will impart a continuous crease or scoreline along the facing material. For example, FIG. 3A shows aconventional creaser wheel 13 that would be used in the creasingprocess. As seen in FIG. 3A, the conventional creaser wheel 13 has anapproximately uniform circumference 13A. Therefore, when applied to thefacing material 1, the conventional creaser wheel 13 will impart acontinuous crease into the facing material. FIG. 3B illustrates such asituation wherein the conventional creaser wheels with approximatelyuniform circumferences have made row of continuous creases or scorelines 15 in the facing material 1.

While the creases created by a creasing process allow the facingmaterial 1 to fold more readily, the creases can also have detrimentaleffects on the facing material 1. First, the facing material 1 may beweakened along a crease. The amount that the facing material 1 isweakened may depend on what material is used as the facing material. Forexample, as discussed above, a fiberglass mat or a pre-coated fiberglassmat can be used as the facing material. However, when the fiberglass matis creased, the fibers in the creased area usually are not smoothly bentor creased. Instead, the fibers in the creased area of the fiberglassmat are often crushed and broken. Therefore, the creasing process canactually cut-through, or sever, the facing material 1. This isdetrimental to the wallboard product 7, because the portion of thefiberglass mat that comprises the edge of the wallboard product 7 mayseparate from the core of the wallboard product 7. As will be discussedin detail below, this reduces the quality and aesthetics of thewallboard product 7.

Alternatively, even if the fibers of the fiberglass mat are not actuallycut-through or severed during the creasing process, the prior artcreasing process will in most cases, at least, weaken the fibers. Thisweakening of the fibers can still cause the portion of the fiberglassmat that comprises the edge of the wallboard to separate from the coreof the wallboard, because when the weakened fibers at the creased areaare further stressed they may break or separate from the rest of thefiberglass mat. In other words, the weakened fibers may still be intactimmediately after the creasing process, but may break or separate fromthe rest of the fiberglass mat at a later time. For example, the fibersmay break or separate during the folding process where the fibers arefurther stressed or during or after the drying process wherein thewallboard contracts as it dries. Similarly, the processes of booking,stacking, bundling, transporting or even installing the wallboard canall cause stress at the edges of the wallboard and, therefore, theseprocesses may cause the weakened fibers to break or separate from therest of the fiberglass mat. Therefore, unfortunately, such damage is notusually apparent until after the wallboard product is complete.

When the weakened fibers at the creased areas break or separate from therest of the fiberglass mat, the portion of the fiberglass mat thatcomprises the edge of the wallboard separates (i.e., “pops open”) fromthe core of the wallboard. When this happens, the aesthetic appearanceand quality of the wallboard product 7 is reduced. FIGS. 4A and B showexamples of where the edge of the wallboard 7 has separated (i.e.,popped open) from the core of the wallboard 7. In the industry, theseproducts are generally considered unsellable. For example, when aconsumer is selecting and purchasing wallboard, they will likely selectand purchase wallboard that has the edges intact over wallboard thatdoes not.

Therefore, for the reasons discussed, the conventional creasing processhas drawbacks, particularly for wallboard made with facing materialcomprising a fiberglass mat and coated fiberglass mat. Further, theconventional creasing processes, such as the conventional creasingwheels discussed above, will impart a continuous crease to the facingmaterial which weakens the facing material throughout the entirety ofcontinuous, creased area of the facing material. The Applicant hasdetermined that such a continuous crease is not needed, because thefolding of the facing material can still be accomplished withoutcreasing the facing material in a continuous manner over entirety of thefacing material. Instead, the Applicant has realized that it is possibleto crease the facing material in a way that the folding of the facingmaterial is still facilitated, but yet reduces the extent that thefacing material is weakened by the creasing process.

Hence, aspects of this disclosure are directed to a method of creasingfacing material that reduces the weakness in the facing material due tothe creasing process. In other words, the facing material is strongeralong the creased portion of the facing material compared to facingmaterial which has been creased by conventional methods. As a result,the Applicant's method of creasing the facing material reduces oreliminates the chance that the portion of the facing material whichcomprises the edge of the wallboard will separate from the core of thewallboard. This method thus results in an improved wallboard product.Therefore, both the quality of the wallboard and its aesthetics arepreserved.

According to one aspect of this disclosure, a method of creasing thefacing material includes creasing or scoring the facing materialintermittently. In other words, the facing material is creased or scoredin intervals, rather than making a continuous crease or score line inthe facing material. For example, aspects of the disclosure relate tocreasing the facing material intermittently in a substantially linearfashion in a first direction (e.g. along the length) of the facingmaterial so that the facing material has a linear series of creasedportions extending in the first direction along the length of the facingmaterial and a series of portions that are not creased extending indirection along the length of the facing material.

According to some aspects of this disclosure, the creased and“uncreased” sections may alternate linearly along the length of thefacing material such that the creased portions are separated from eachother by the portions that are not creased. In other words, the methodmay include creasing a first section of the facing material, refrainingfrom creasing a second section of the facing material adjacent the firstsection of the facing material, creasing a third section of the facingmaterial adjacent the second section of the facing material, etc. Forexample, the method may include producing facing material that hascreased portions separated from each other by gaps of uncreased facingmaterial. In this way, uncreased portions of the facing material arepositioned in line with the creased portions of the facing material andbetween the creased portions of facing material.

By creasing only some portions of the facing material along a line,instead of the entirety of the facing material along the line, thefacing material retains its strength in those portions of the facingmaterial that are not creased, because the fibers in those sections havenot been stressed by the creasing process. Therefore, more of theoverall strength of the facing material is better retained, but thefacing material is still able to be readily folded.

This method of intermittently creasing the facing material will reduceor eliminate the issue of cutting-through or weakening of the facingmaterial. Therefore, separation of the facing material which comprisesthe edge of the wallboard from the core of the wallboard will bereduced. Hence, through this method both the aesthetics and the qualityof the wallboard are preserved. As a result, materials, time and effortused in manufacturing the wallboard are conserved and waste, in the formof unsellable wallboard product, is reduced.

According to some aspects of this disclosure, the facing material iscreased intermittently in a series of parallel rows extending in adirection along a length of the first layer of facing material. Forexample, as will be described in more detail below, creasing the facingmaterial intermittently may include creasing the facing materialintermittently on a first side of the facing material in order to createa first series of parallel rows on a first side of the facing materialand also creasing the facing material intermittently on a second side ofthe facing material in order to create a second series of parallel rowson a second side of the facing material.

Further, according to some embodiments of the disclosure, the length ofthe creased portions may be uniform and similarly, the length of theuncreased portions can also be uniform. In other words, in someembodiments, the length of the creased portions may be ½ inch and thelength of the uncreased portions may be ⅛ inch. Of course the length ofthe creased portions and the length of the uncreased portions can beequal. For example, the creased portion may be ½ inch while theuncreased portions are also ½ inch. However, it is noted, that neitherthe length of the creased portions, nor the length of the uncreasedportions has to be uniform. For example, in some embodiments the lengthof the creased portions may change from ¼ inch in some areas to ½ inchin other areas and similarly the length of the uncreased portions mayalso change. Additionally, it is noted changes in the length of thecreased portions do not have to correspond to similar changes in lengthof the uncreased portions. For example, in some embodiments the creasedportions may change from ¼ inch in some areas to ½ inch in other areas,while the length of the uncreased portions stays constant at ⅛ inch orvaries between ⅛ inch and 1/16 inch. While the particular dimension ofthe creased and uncreased portions may change, as long as the sequencingand lengths of the creased portions and uncreased portions allow thefacing material to be readily folded and also retains the strength ofthe facing material 1 along the line, the lengths and the sequencing areconsidered within the scope of the disclosure. For example, the lengthof the creased portions and uncreased portions can be 1/32 inch, 1/64inch, 1/16 inch, 3/32 inch, ⅛ inch, 5/32 inch, 3/16 inch, 7/32 inch, ¼inch, etc.

According to some aspects of this disclosure, along a row of creasedportions and portions that are not creased, the percentage of the rowthat is creased is at least 50% of the row. In this way, at least halfof the row is creased while the remaining portion or the row is notcreased. It is noted that is percentage is merely an example and otherpercentages are contemplated. For example, along a row of creasedportions and portions that are not creased, the percentage of the rowthat is creased (i.e., the creased portions) could be approximately:70%, 80%, or 90%. Alternatively, the percentage of the row that iscreased could be less than 50% (e.g., 30%). It is noted these are merelyexamples and other percentages are contemplated. As long the as thepercentages of creased portions compared with the percentage of portionsthat are not creased allows the facing material to be readily foldedwhile not significantly degrading the strength of the facing material inthe creased portion, as encountered in the prior art, the ratios andpercentages are considered within the scope of the disclosure.

Further, it is noted, along a row of creased portions and portions thatare not creased, the ratio of the number of creased portions and thenumber of portions that are not creased can be 1:1. For example, if acrease is made, then an uncreased portion is also made. Thus, if acrease with a length of ¼ inch is made in the facing material, it couldbe followed by an uncreased portion of the same length of ¼ inch. Inother words, the lengths of the individual creased portions and thelengths of the individual portions that are not creased may beapproximately equal.

The method of intermittently creasing the facing material can beaccomplished in a variety of ways. For example, a rotating means, suchas a creaser wheel or scoring wheel, may be used to intermittentlycrease the facing material. Similarly, a reciprocating means, such as areciprocating stamping mechanism may be used to intermittently creasethe facing material. Similarly, a track means, such as a creasing meansthat moves like a belt or tank tread, can be applied to the facingmaterial to intermittently crease the facing material As long the facingmaterial is intermittently creased, the actual means or mechanism forcreasing the facing material is considered within the scope of thedisclosure.

According to one aspect of this disclosure, the method of intermittentlycreasing the facing material includes a rotating creaser apparatus. Forexample, the method of intermittently creasing the facing material mayinclude one or more creaser wheels. An illustrative embodiment of acreaser wheel according to one aspect of the disclosure is shown atFIGS. 5A and 5B. As shown in FIGS. 5A and 5B, the illustrative creaserwheel 17 is a disc with a circumference. In the depicted embodiment, thecircumference includes notches 19 which define teeth 21. In the depictedembodiment, the notches 19 have angled shape in a direction towards thecenter of the wheel 17 which define the teeth 21. FIG. 5C is an enlargedview of the notches 19 which show that in the depicted embodiment, theangle of the notches is approximately 120°. However, this configurationis merely an illustrative embodiment and other shapes and angles couldbe employed without departing from the scope of the disclosure.

FIG. 5D is an end view of the creaser wheel illustrated in FIG. 5A. Asseen in FIG. 5D, the thickness of the creaser wheel 17 can remainrelatively uniform throughout the wheel until the thickness of thecreaser wheel begins to taper to a point near the circumference of thecreaser wheel 17. For example, FIG. 5E is a sectional view of thecreaser wheel illustrated in FIGS. 5A and B. As can be seen in FIG. 5E,the taper (α) can be approximately 6°.

According to some aspects of the disclosure, the creaser wheel 17 mayinclude an inner portion 17A and an outer portion 17B. The inner portion17A may include structure for the mounting the creaser wheel 17 on arotational means for rotating the creaser wheel 17, while outer portion17B contains the teeth 21 for creasing the facing material 1. As seen inFIG. 5A, the inner portion 17A may include one or more apertures forsecuring the creaser wheel to the rotational means. As seen the depictedembodiment, inner portion 17B includes a center aperture and threeadditional smaller apertures. The creaser wheel 17 could be mounted onthe rotational means by fitting the apertures on a series of pegsprojecting from the rotational means. Conventional securing means suchas washers, nuts, etc. may be used to secure the creaser wheel 17 to therotational means. It is noted that the creaser wheel 17 could be asingle integral piece. Additionally, it is noted that the creaser wheelcould be constructed from a metal, such as 400 stainless steel. Othermetals and alloys could also be used as desired without straying fromthe spirit of the disclosure.

As seen in FIG. 5A, the depicted embodiment has 32 teeth. However, thisis merely an illustrative embodiment and other quantities of teeth areconsidered within the scope of the disclosure. For example, according tosome embodiments the number of teeth could be more (e.g., 48 or 64teeth) or less (e.g., 16 or 24 teeth). It will be understood by those ofordinary skill in the art, that the dimensions of the notches 19, thedimensions of the teeth 21, and the number of teeth 21 can be configuredto provide the above described percentages and ratios of creasedportions and uncreased portions. For example, the notches 19 and theteeth 21 could be configured to provide the facing material 1 with apercentage of creased portions compared with the percentage of portionsthat are not creased of 50% to 50%. Of course, the notches 19 and theteeth 21 could be configured to provide other percentages and ratios aswell. Similarly, the notches 19 and the teeth 21 can be configured toprovide the above described uniform or non-uniform lengths of thecreased and uncreased portions described above. For example, the notches19 and the teeth 21 could be configured to provide the facing material 1with creased portions of ⅛ inch and uncreased portions of ⅛ inch. Ofcourse, the notches 19 and the teeth 21 could be configured to provideother lengths as well.

The dimensions of the notches 19 and teeth 21 along with the distancethat the creaser wheel 17 is positioned from the facing material 1 willaffect the depth of the crease or score line created in the facingmaterial 1. The dimensions of the creaser wheel 17 and distance betweenthe creaser wheel 17 and the facing material 1 should be configured sothat the creases made in the facing material 1 facilitate folding offacing material, but at the same time the facing material 1 is notcut-through or severed. For example, if fiberglass mat, including acoated fiberglass mat, is used as the facing material, its thickness mayrange from approximately 10/1000 of an inch to 40/1000 of an inch. Thenotches 19 and teeth 21 of the creaser wheel 17 should be taken intoaccount and the creaser wheel 17 should be positioned accordingly sothat the fiberglass mat is not cut-through or severed. Similarly, ifpaper is used as the facing material its thickness may range fromapproximately 10/1000 of an inch to 20/1000 of an inch. Again, thenotches 19 and teeth 21 of the creaser wheel 17 should be taken intoaccount and the creaser wheel 17 should be positioned accordingly sothat the paper is not cut-through or severed.

It is noted that each of the facing materials have differentcharacteristics. For example, the depth of the crease on the fiberglasstypically needs to be more shallow (or “lighter” than that on paper).

Another illustrative embodiment of a creaser wheel according to anaspect of the disclosure is shown at FIGS. 6A and 6B. As shown in FIGS.6A and 6B, the illustrative creaser wheel 23 has notches 25 and teeth27. As shown, the teeth 27 protrude from the circumference of thecreaser wheel 23 and the notches 25 are defined by the teeth 27. As seenin the depicted embodiment, the teeth 27 exhibit a rounded, orscalloped, shape. Further, similarly to the previously describedembodiment, the creaser wheel 23 may include an inner portion 23A and anouter portion 23B. The inner portion 23A may be directed to the mountingof the creaser wheel 23 on a rotational means for rotating the creaserwheel 23, while outer portion 23B contains the teeth 27 for creasing thefacing material 1. As seen in FIGS. 6C-D, the inner portion 23A may bethicker than the outer portion 23B. Further, as FIG. 6E, the teeth 27can exhibit a taper (θ) and the taper can be approximately 30°. It isnoted that according to at least some embodiments, the outside diameterof the creaser wheel can range from 4.25 inches to 4.5 inches and thethickness of the creaser wheel can ranges from 0.100 inches to 0.125inches.

Another illustrative embodiment of a creaser wheel according to anaspect of the disclosure is shown at FIGS. 7A and 7B. As shown in FIGS.7A and 7B, the illustrative creaser wheel 29 has notches 31 and teeth33. This embodiment is similar to the embodiment shown in FIGS. 6A-E.However, the notches 31 have a rounded shape extending towards thecenter of the creaser wheel 29, while the teeth 33 are relativelyrectangular. It is noted that these three embodiments are merelyillustrative and should not be considered as limiting. Instead, they areprovided merely to aid the reader in understanding and appreciating thedisclosure. As long the creaser wheel can provide the ratios and thepercentages of creased portions compared with the percentage of portionsthat are not creased which allow the facing material to be readilyfolded without significantly degrading the strength (i.e., helping toretain strength) of the facing material in the creased portion, thecreaser wheels are considered within the scope of the disclosure.

FIG. 8 shows an illustrative embodiment of a set of four creaser wheels13A-D positioned at one side of the facing material according to oneaspect of this disclosure (it is noted that as shown in FIG. 9B, acorresponding set of four creaser wheels would be positioned on a secondside of the facing material 1, but for simplicity only this first set ofcreaser wheels 13A-D will be discussed in detail). As seen in FIG. 8,respective anvils 13E-H are located below each creaser wheel 13A-D. Theanvils are notched around their circumference in order to provide anoverlap with the circumferential edge of the creaser wheel. Therefore,the facing material 1 being fed between the creaser wheels 13A-D and theanvils 13E-H is creased or scored in the overlap between thecircumferential edge of the creaser wheels and the notchedcircumferences of the anvils. The anvils 13E-H may be mounted on lowtorque bearings so that they rotate along with the feeding of the facingmaterial 1. This aids in preventing breaks in the facing material 1 asit is fed through the creasing area 11.

The creaser wheels 13A-D may be positioned offset from each other in thewidth direction of the facing material 1 so that the creaser wheels13A-D can create a series of parallel rows of creased portions anduncreased portions in the facing material 1. The series of parallel rowsof creased portions and uncreased portions extend in a direction along alength of the first layer of facing material. The illustrativeembodiment of FIG. 8 can make up to four parallel rows in the facingmaterial 1 on one side of the facing material 1. FIG. 9A shows anillustrative embodiment of a facing material 1, wherein two parallelrows have been made on each side of the facing material 1. As seen inFIG. 9, the parallel rows each include a series of creased areas 34 anduncreased areas 35.

It is noted that while FIG. 8 shows creaser wheels 13A-D, otherembodiments may have more or less creaser wheels depending on the typeof wallboard to be manufactured. Further, not all the creaser wheelshave to be used during a particular process. For example, while theillustrated embodiment of FIG. 8 includes four creaser wheels 13A-D, inorder to manufacture the rectangular edge of the wallboard shown in FIG.2A, only two of the four creaser wheels 13A-D are needed, because theembodiment shown in FIG. 2A requires only two folds. Therefore, in thatsituation, not all of the creaser wheels 13A-D would be used.

Further, it is noted that according to some aspects of this disclosure,the spacing of the creaser wheels will determine the thickness of thewallboard product 7. For example, if a particular wallboard product witha rectangular profile, as shown in FIG. 2A, is to be X feet wide and Yinches thick, then, as seen in FIG. 9B, the first crease (correspondingto position 9A shown in FIG. 2A) should be made approximately 0.5X feetfrom the center of the facing material 1, because as seen in FIG. 2Athis first crease will define the edge of the wallboard 7. The secondcrease (corresponding to position 9B shown in FIG. 2A) should be madeapproximately Y inches from the first crease because as seen in FIG. 2Athis second crease will define the thickness of the wallboard 7. Asshown in FIG. 9B, the first and second creases should be made far enoughaway from the edge of the facing material 1 that enough facing materialis left to create the top flap (corresponding to flap 9C shown in FIG.2A) in order for the top facing material sheet 2 to be attached to thefacing material 1. As discussed above, the thickness of the wallboardproduct will depend on the distance between the first and secondcreases. Hence, if the thickness of the wallboard product is ¼ inch,then the spacing between the first and second creases would be about ¼inch. According to some illustrative embodiments of the disclosure, thewallboard can ¼, 5/16, ⅜, ½, and 1 inch thick. It should be noted thatall the distances and dimensions discussed above are merely approximate.For example, the wallboard product 7 may contract upon being dried inthe dryer station. Such contraction will obviously have to be taken intoaccount in positioning the placement of the creases upstream.

It is noted that while some of the above disclosure discusses afiberglass mat and coated fiberglass mat as the facing material, becauseof the fiberglass fibers' greater potential for breakage and cut-throughcompared with paper fibers, this should not be construed to mean thatthis process can not be applied to paper. In fact, even though paperfibers show a greater tendency to bend during the creasing process asthe paper comes into contact with the creaser wheel, the paper is stillweakened at the crease. Therefore, the method of intermittently creasingthe facing material of the present disclosure will help the creasedpaper retain strength, just as it does with the fiberglass mat. Thus,even when applied to paper, this method will aid in preserving theintegrity of the wallboard product 7 and preventing the facing material1 which comprises the edge of the wallboard product 7 from separating(i.e., popping open) from the core of the wallboard product 7.

While the disclosure has been described with respect to specificexamples including presently preferred modes of carrying out thedisclosure, those skilled in the art will appreciate that there arenumerous variations and permutations of the above described structuresand methods. Thus, the spirit and scope of the disclosure should beconstrued broadly.

What is claimed is:
 1. An apparatus for manufacturing wallboard comprising: a feeder that advances a first layer of facing material along a wallboard production line; a first set of one or more creaser wheels positioned along the production line adjacent a first edge of the first layer of facing material; a second set of one or more creaser wheels positioned along the production line adjacent a second edge of the first layer of facing material; and a feeding source along the production line that feeds a gypsum slurry onto the first layer of facing material, wherein each of the creaser wheels includes an alternating series of notches and teeth, each set of creaser wheels creating a series of uncreased and creased portions in a line in the first layer of facing material, and wherein the notches of each creaser wheel have an angle of approximately 120°.
 2. The apparatus for manufacturing wallboard according to claim 1, further comprising: a second feeder for feeding a second layer of facing material along the wallboard production line; a folding apparatus which folds the creased first layer of facing material along creases created by the one or more creaser wheels; a forming apparatus for attaching the second layer of facing material to the first layer of facing material over the slurry; and a drier for drying the gypsum slurry between the first and second layers of facing material.
 3. The apparatus for manufacturing wallboard according to claim 1, wherein each of the creaser wheels in the first set of creaser wheels is offset from one another in a lateral direction across a width of the first layer of facing material, so that the first set of creaser wheels creates a first set of parallel lines of creased portions and uncreased portions extending in a first direction of the first layer of facing material, and further wherein each of the creaser wheels in the second set of creaser wheels is offset from one another in the lateral direction across the width of the first layer of facing material, so that the first set of creaser wheels creates a first set of parallel lines of creased portions and uncreased portions extending in a direction in the first direction of the first layer of facing material.
 4. The apparatus for manufacturing wallboard according to claim 3, wherein each of the creaser wheels in the first and second set of creaser wheels are spaced apart by about ¼ inches to about 1 inch.
 5. The apparatus for manufacturing wallboard according to claim 3, wherein each of the creaser wheels in the first and second sets of creaser wheels are spaced apart by about ½ inch to about 1 inch.
 6. The apparatus for manufacturing wallboard according to claim 1, wherein each creaser wheel is configured to create creased portions comprising 30% to 90% of the line.
 7. The apparatus for manufacturing wallboard according to claim 1, wherein the notches and teeth are configured to create individual creased portions and individual uncreased portions having an approximately equal length.
 8. The apparatus for manufacturing wallboard according to claim 1, wherein each creaser wheel is configured to create creased portions comprising at least 50% of the line.
 9. The apparatus for manufacturing wallboard according to claim 1, wherein each creaser wheel has a thickness ranging from 0.100 inches to 0.125 inches.
 10. The apparatus for manufacturing wallboard according to claim 1, wherein each creaser wheel has an outside diameter from 4.25 inches to 4.5 inches.
 11. The apparatus for manufacturing wallboard according to claim 1, wherein each creaser wheel comprises from 16 to 64 teeth.
 12. The apparatus for manufacturing wallboard according to claim 1, wherein the teeth have a rounded shape.
 13. The apparatus for making wallboard according to claim 1, wherein the teeth have a rectangular shape.
 14. The apparatus for manufacturing wallboard according to claim 1, wherein each of the creaser wheels comprises an opposing anvil.
 15. The apparatus for manufacturing wallboard according to claim 14, wherein the anvils comprise a notched circumference for receiving a circumferential edge of the respective creaser wheels.
 16. The apparatus for manufacturing wallboard according to claim 1, wherein the notches and teeth of the creaser wheels are configured to provide creased portions having a length of 1/64 to ½ inch.
 17. The apparatus for manufacturing wallboard according to claim 1, wherein each creaser wheel has a taper (a) of approximately 6°.
 18. The apparatus for manufacturing wallboard according to claim 1, wherein the teeth of each creaser wheel have a taper (Φ) of approximately 30°.
 19. The apparatus for manufacturing wallboard according to claim 1, wherein the facing material comprising a fiberglass mat or a coated fiberglass mat and the creaser wheels are dimensioned and positioned to prevent cut-through or severing of the fiberglass mat or the coated fiberglass mat.
 20. The apparatus for manufacturing wallboard according to claim 1, further comprising a folding apparatus which folds the creased first layer of facing material along creases created by the one or more creaser wheels, after the gypsum slurry is fed onto the first layer of facing material. 